1[Classic Versatile] Adopts the appearance of mainstream big sunglasses, classic and generous, fashionable and versatile, suitable for various sports venues. 2[With Stereo Headset] With two stereo headsets, you can listen to music, and you can answer calls through BT connection. 3[PC Double Lens] adopts PC double lens, wear resistant, environmentally friendly, resistant to aging, high hardness and strong bearing capacity. 4[Ergonomic Design] Ergonomic design ensures that it will not fall off easily during exercise, and it can effectively prevent ultraviolet rays from damaging the eyes. 5[Rotating Earphone, Reversible Lens] The earphone can be rotated 270; the lens can be turned 180, detachable and replaceable. Item Type: Sunglasses Material: Plastic Colour: Black Memory Size: 128M-32GB Play Format: MP3, WMA, ASF, WAV USB Interface: Standard USB2.0 Headphone Power: 20Hz-20KHz Signal to Noise Ratio: 90dB Distortion Rate: 0.1% Battery Voltage: 3.7V Battery Type: Lithium Battery: 180mAh (Delivered with Inbuilt Battery) Charging Time: About 2-3 Hours Music Format: MP3/WAV/WMA Hardware: For IBM PC/AT or Compactable PCak Laptop and USB Port Computer Operating System: For Window98/SE/ME/2000/XP BT Technical Specifications: 1: Conform to the BTV4.0 Version 2: Frequency 2.4GHZ 3: Maximum Transmission Range 10M 4: Continuous Talk Time 3-5 Hours 5: o Decoding 15Bit 6: Signal to Noise Ratio>60dB 7: Normal Standby Time 5-7 8: Working Temperature -10-55 1 x Wireless Glasses 1 x USB Cable 1 x User Manual 1 x Dust Cloth 1 x Storage Box The inbuilt battery is .